Read the excerpt from part 2 of "Flowers for Algernon." They're all pretending that Algernon's behavior is not necessarily significant for me. But it's hard to hide the fact that some of the other animals who were used in this experiment are showing strange behavior.

How does Algernon’s behavior affect Charlie and affect the plot?

It makes Charlie excited about the possibility that his research will become more interesting.
It makes Charlie realize that he must protect himself from ending up like the mouse.
It makes Charlie excited that he will have a lot of time to complete his studies.
It makes Charlie realize that he must finish his research as quickly as possible.